The present disclosure relates generally to the formation of ceramic lithium-ion solid electrolytes, and more specifically to a reactive sintering process for forming dense, hermetic electrolyte membranes.
Solid electrolytes, also known as fast ion conductors, are materials that can function as solid state ion conductors and can be used, for example, in solid oxide fuel cells and lithium-ion batteries. In a lithium-ion battery, for example, lithium ions move from a negative electrode to a positive electrode during discharge (and back when charging) via the solid electrolyte. The solid electrolyte, such as lithium aluminum titanium phosphate (LATP), can conduct lithium ion through vacancies in the LATP crystal lattice. In Li-ion batteries, the solid electrolyte membrane can provide a hermetic barrier between the anode and the cathode in order to prevent the anode and cathode from sharing a common electrolyte solution.
Thus, important to the development of Li-ion batteries is the availability of dense, conductive lithium-ion electrolyte membranes. A major challenge for such membranes is the desire to sinter suitable materials to sufficient density such that the membrane is hermetic while providing sufficient conductivity and economy. Conventional hermetic membranes, for example, which are commonly made using a glass-ceramic process, can be made dense and hermetic, but typically at the expense of other attributes such as conductivity and cost. A challenge facing the conventional glass-ceramic process is the requirement that the desired composition form a stable glass.
In view of the foregoing, it would be desirable to develop a process for forming dense, hermetic, Li-ion conductive ceramic electrolyte membranes without such a limitation to stable glass formation. As used herein, a hermetic membrane is substantially impervious to the diffusion of liquids or gasses.
Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operations of the invention.